Governing mechanism for load-hoisting machines



Oct. 9, 1928.

N. wARsHAw GOVERNING MECHANISM FOR LOAD HOISTING MACHINES Filed June 21, 1926 2 Sheets-Sheet 1 InvenTor. NaThuniel Worshuw A'flys Oct. a, 1928. 1587,186

N. WARSHAW GOVERNING MECHANISM FOR LOAD HOISTING MACHINES Filed June 21, 1926 2 Sheets-Sheet 2 InvenTor. NuThun'lel Wczrshclw WM wkm ATTys.

Patented 0st. 9, 1928.

NATHANIEL NARSHAW, OF

noscron, nassacnusn'r'rsnssienon '10 LEWIS-SHEPARD COMPANY, OF'WATERTOWN, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

Application filed June 21,

This invention relates to improvements in load hoistingmachines, and the general object thereof is to provide governmgmechanism automatically operable'by anmcrease in the speed of the movement of the load beyond predetermined speed to arrest the movement of the load.

More specifically, the invention relates to governing machanism for load hoist1ng machines, such as winches, comprising fluid controlled means for arresting the descent of the load whenthe speed at which it descends exceeds a predetermined amount.

A further object of the invention is to provide a fluid controlling means of the character above described which is actuated by the rotation of the winding drum of the winch.

A further object of the invention is to provide a fluid "controlling device operable by the rotation of the winch drum 1n excess of a predetermined speed to actuate the braking mechanism of the winch.

A further ob ect of the 1111 611131011 1s to provide a simple this character which may be applied to the usual types of hoisting machines without material modification. of the construct on V employed. As illustrated'herein the brak thereof. I

Other objects and features of the invention vill more fully appear from the following description and the accompanying drawings, and will be particularly pointed out in the claims. I

Inasmuch as the present invention is applicable to the usual type of hoisting machines it is only necessary to show so much of a. typical hoisting, machine as will illustrate the application of the invention thereto. A preferred embodiment of the invention is illustrated in the accompanying drawings in which H I 'F 1 is a view of a winch actuating and raling mechanism illustrating the present invention applied thereto, cylinders andpis tons of the fluid controlled mechanism beingshown' in vertical section, and port-ions of the frame also shown in vertical section.

' Fig. 2 is a similar frontelevation of a. similar controlling mechanism,in which a single cylinder and co-operating piston is employed instead of two, as illustrated in Fig. 1.

fluid controlling device of GOVERNING MECHANISM FOR LOADJIOISTING: MACHINES.

1926. Serial No. 117,588.

Preferred embodiments of the invention are illustrated herein as applied to the winch mechanism of a hoisting machine such as that illustrated in the application ofFrederick J. Shepard, Jr., and lSIathaniel WVarshaycv, Serial. No. 86,820 filed February 8, 192

The winch mechanism illustratedherein comprises a rectangular frame having vertical standards 1, which are connected at the lower end by angle bars 2,3vhich may be secured to a suitable base, and at the top by a plate 3, which is welded'or otherwise secured to standards 1. The winding drum 1 is fixedly secured to a shaft 5, whichis mounted in suitable -bearings in the standards 1, and a cable 6, extends from the w-inding drum upwardly over a sheave (not shown) andis connected at its opposite end to a suitable load supporting m'eans, such as the platform of a hoisting machine. A gear 7 which is secured to the winding'drum or its shaft engages apinion 8, upon a driving shaft 9, which isjournalled in the standards ing mechanism comprises a brake drum 10,

having hub which is rotatably mounted upon the driving shaft 9, and is engaged by semi-circular brake bands 11,12, which are provided at the upper 14:, which are secured together by a bolt 15, the brackets being held in spaced relation by a spiral spring 16. The lower ends of the brake bands 11, 12 are connected to suitable brake applying levers, as will hereinafter more fully appear.

The brake drum .10 is provided. with aflange 17. which is adapted to be detachably connected to the shaft 9, by suitable clutch mechanism, which as illustrated herein comprises a plurality of pivotally connected brake shoes 18, 19, 20. The adjacent ends of the brake shoes 18, 20, are pivotally connected respectively to toggle links 21, 22, the knuckle joint, 23, of which is connected by a link 24, to an arm 25, which is fixedly secured to the shaft.

r The brake bands ll, 12, are normally apends with brackets 13,-

V plied to the fiange'17, of the brake drum, and

prevent rotation of the drum. In the winding up of the winch drum the rotation of the driving shaft 9, in a clockwise direction causes the arm 25, and link 24, to draw the toggle links 21, 22, toward the shaft 9, thereby releasing the clutch shoes 18, 19, 20, from engagement with the drum, and permitting free rotation of the driving shaft. Upon completion of the winding up movement a slight counter clockwise rotation of the driving shaft causes the arm 25, and link 24,to expand the toggle and to apply the brake shoes to the brake drum, thereby preventing reverse rotation of the Winding drum.

The brake applying and actuating mechanism comprises two bell crank levers 26, 27, which are respectively pivotally mounted upon studs 28,29, extending from one of the vertical standards. The vertical arms of the bell crank levers 26, 27, are pivotally connected respectively to the lower ends of the brake bands 11, 12. The horizontal of the bell crank lever 26, is provided with a pin 30, whichis engaged by a bifurcated end 31, of the horizontal extension of the bell crank lever 27. The other horizontal arm 32, of the bell crank lever 27, is provided with a spheroidal head 33, which is apertured to receive a vertical rod 34, the

lower end portion of which is slidably mounted in a bracket 35, which is secured to standard 1. The spheroidal head of the horizontal arm 32 of the bell crank lever engages a collar 36, which is secured to the rod 34, and rests upon the end of a spiral spring 37, the lower end of which is mounted upon a cross head 38, which rests upon the upper end of aheavier spiral spring 39,

which is supported upon the bracket 35.

The cross head 38, is connected by a pair of links 40, (one of which is shown) to a bifurcated end 42, of an arm 43, which is fixedly secured to a stud shaft 44, having an angular end portion adapted to be engaged by the operating crank.

In order to release the brake and thereby permit reverse rotation of the winding drum to lower the load, a crank is applied to the head of the stud shaft 44, and rotated in a counter clockwise direction. Such rotation of the shaft depresses the arm 43, and

, through the links 4O depresses the cross head 38, against the force of the spring 39, thereby relieving the pressure which acts through spring 37 upon the arm 32, of the brake applying lever 27, and through it upon the brake applying lever 26, so that the brake hands are released from effective engagement with the brake drum, thereby permitting reverse rotation of the driving shaf and winding drum. 4

The mechanism above described is disclosed in the prior application of Shepard and Warshaw, above identified.

While a hand-operated mechanism for rotating the winch drum is illustrated and described herein, it is obvious that suitable power mechanism may be employed for rotating the driving shaft, such for example as an electric motor mounted upon the top plate 3, of the frame, or any other suitable arrest the descent of the load when a predetermined speed is exceed. I

The mechanism for accomplishing this purpose illustrated herein serves to apply the brake, but it will be obvious that such mechanism may be employed to control other mechanisms.

The particular form of controlling mechanism which is illustrated in Fig. 1 of the drawings comprises a plurality of cylinders 45, 46, which are pivotally mounted at the lower ends upon the arm 47, of the brake actuating lever, the other arm 48, of which engages the lower end of the brake 210131121"- ing rod 34. The brake actuating lever is pivotally mounted upon a stud or fulcrum 49, projecting from thestandard 1. I

The fluid-containing cylinders 45, 46, are of similar construction,-and are respectively provided with tubular pistons 50, 51, having at their upper endspiston rods 52, 53, which are connected respectively to opposite ends of a lever 54, 'whichis fulcrumed at its centre upon stud 55 projecting from the standard 1. 7 I v The piston rod 52, is also pivotally connected to an arm 56, of the eccentric strap 57, which embraces aneccentric 58, which is secured to the shaft 5, of the winding drum.

The invention in its broad sense contemplates the provision of means for permitting relative reciprocating movement between the piston and cylinder during normal speeds of rotation of the winding drum,

or descent of the load, which will not subof the load, is attained, to produce a relative bodily displacement of said cylinder and piston, and the provision of means which is operable by such displacement to apply the brake, or otherwise to arrest the rotation of the winding drum, or the descent of the load. s

In the preferred construction illustrated in the drawings the pistons 50, 51, are provided at their lower ends with heads 59, 60,

of similar construction, head 59 being shown into the compression chamber, but which will, by the closing of the valve upon the downward movement of the piston, prevent the fluid from flowing from the compression chamber through the piston head. The piston head isalso provided with a restricted passage which as illustrated herein in its simplest form 1s a port 64, extending through the piston head, and which'is of such cross sectional area as to permit a sufliciently free flow of fluid through it during'the recipro cation of the piston at normal speeds 'as to avoid substantial increase 'in'fluid pressure in the compression .chamber of the cylinder. The area ofthis port, however, is suchthat when the speed of reciprocation of the piston exceeds a predetermined amount the fluid pressure'in the compression chamber of the cylinder will be increased, thereby causing the cylinder to be pressed downwardly against the arm 47, of the brake actuating lever, thus causing the arm 48, to-push vthe brake actuating rod 44 upwardly and.

through it to actuate the brake applying levers 26, 27, thereby causing the brake bands to grip the brake drum and arrest the rotation of the driving shaft, and

through it to arrest the rotation of the wind ing drum.

Inasmuch as the cylinders 45, 46, are located at different distances frointhe fulcrum 49, of the bralre actuatinglever, the port 64, in the head 60, of the piston 51, may be made of such larger diameter than the port iii) 64, of the piston head 63, as to effect a building up of pressure inthe compression chamber of the cylinder 46, equal to that which is built up inthe compression chamber 62, of the cylinder 45.

In the operation of the device, therefore, the winding up of the cable upon the winch drum will be accomplished by applying the operating crank to the head of the driving shaft 9, and rotating the crank in a clockwise direction. hen the load has been elevated to the desired height, release of the winding crank will cause the driving shaft to be rotated slightly in a counterclockwise direction,

thereby applying the brake shoes to the inner,

face of the flange of the 'brake drum, it being understood that at this time the brake,

straps are applied to the brake drum by the actionsof the springs 37, 39, upon the brake applying levers 27, 26. Thus the load will be locked in its elevated position. When it is desired to lower the load the operating handle will be applied to the end of the stud shaft 44, and rotated in a counter clockwise direction, ythus depressing spring 39, r

and releasing the pressure applie through thespring 37, so that the brake shoes will be gradually released from engagement with the brake drum. This will permit reverse rotation of the winding drum. As the eccentric 58, is secured to shaft 5, of

sion chambers. However, when the speed of rotation of the winding drum exceeds a predetermined amount the fluid will not be able to pass through the restricted ports 64, in the'piston' heads with sufficient rapidity to accommodate the rapid reciprocation of the pistons. Therefore, the pressure will be built up in the compression chambers which will force the cylinders bodily downwardly, therebypushing the arm 47, of the brake actuating lever downwardly and causing the arm 48, to raise the brake applying rod 34, thus causing the brake applying levers 27, 26, to apply the brake bands to the brake so that the rapid descent of the load will be arrested.

In Fig. 2 a similar construction is illus-' trated, in which a single cylinder 65, is

pivotally mounted upon the arm 47, of the brake actuating lever. The piston 66, illustrated in this figure is of the tubular type, and is provided with a head 67, having a valve controlled port 68, to permit the free flow of the liquid therethrough during upward movement of the piston, and to prevent the liquid from flowing therethrough during the downward movement of the piston, and is provided also with a restricted port 69, which'aots in the manner above d by .it

the winding drum, the reverse rotation ofv 56, of the eccentric strap, as heretofore described. The piston, however, is provided with an external sleeve 72, which slidably fits the outer wall 73, of the cylinder which is shown herein as of somewhat smaller diameter and less thicknessthan the. wall of the compression chamber ofthe cylinder. The sleeve '72 serves to prevent dust and grit from entering the cylinder and also to prevent splashing of oil from the cylinder. The operation of the mechanism illustrated in Fig. 2 is identical with that shown in Fig. 1, and need not be further described.

It will be obvious that the action of the fluid controlling mechanism in the construction shown in Fig. 2 will be somewhat more intermittent than the duplex controlling mechanismillustrated in Fig. 1, but this construction is somewhat cheaper of manufacture, and is adapted to operate successfully upon lighter duty hoisting machines.

It will be understood that the embodiments of the invention disclosed in the acticularly referred to herein.

Laving thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

1. Governing mechanism for load hoisting machines comprising a fluid-containing cyl-' inder and piston, means operable by the movement of tne load for producing a normal relative reciprocating movement therebctween, means permitting relative bodily displacement of said cylinder and piston, moans acting respectively to permit the fluid to flow to and from the compression chamber of the cylinder without substantially increasing the fluid pressure therein during normal relative reciprocating movements of said piston and cylinder, but operable upon increase in such relative movement in excess of predetermined speed to increase the pressure in said compression chamber, and thereby'cause relative bodily displacement of said cylinder and piston, and means operable by such relative bodily displacement to arrest the movement of the load.

2. Governing mechanism for load hoisting machines having a brake comprising a fluidcontaining cylinder, a piston reciprocable therein, means permitting relative bodily displacement of said cylinder and piston, means operable by the normal movement of the load to reciprocate said piston, means for permitting the fluid to flow to and from the compression chamber of said cylinder without substantially increasing the pressure Les /use therein during normal speeds of reciprocation of the said piston, but operable upon increase in the speed of reciprocation in excess ;of predetermined speed to increase the pressure in said compression chamber, and means operable by such increase in pressure to cause relative bodily displacement of said cylinder and piston and means operable thereby to actuate saic brake.

Governing mechanism for load hoisting machines having a'brake, comprising a fluid containing cylinder connected to and movable with said brake, a piston reciprocable in said cylinder, means operable by the movement of the load for reciprocating said piston, means acting respectively to permit the fluid to flow to and from the compression chamber of said cylinder without substantially increasing the fluid pressure therein during normal speeds of reciprocation of said piston, but operable upon increase in the speed of reciprocation in excess of a predetermined speed to increase the pressure In s id compression chamberythereby causa bodily movement of said cylinder operable to actuate said brake.

Zr. Governing mechanism for load hoisting machines having a brake,a brake actuating lever, a plurality of fluid-containing cylinders connected to and movable with said brake actuating lever, pistons in said cylinders, means operable by the movementof the load for r ciprocatingsaid pistons in sequence, means acting to permit the fluid in the respective cylinders to flow to and from the. compression chambers thereof without substantially increasing the pressure thereon during normal speeds of reciprocation of said piston, but operable upon increase in the speed of reciprocation in XC es of a predetermined speed to in crease the pressure in the respective cylinders, thereby causing bodily movement of said cylinders operable to actuate said brake. 5. Governing mechanism for winches comprising a fluid-containing cylinder, a piston movably mounted therein, means operable by the rotation of the winding drum to actuate said piston, means normally operable to tr; uiit luid from one side of the piston to i without substantially increasing the l' i p essure in the cylinder, but operable i increase in speed of reciprocation in excess a predetermined'speed to increase the fluid pressure in said cylinder,

and means operable by such increasedpres sure to arrest the'rotation of the winding drum.

6. Governing mechanism for winches comprising a fluid-containing cylindeiga piston, rcciprocable therein, means operable by the rotation of the winding drumto reciprocate said piston, means permitting fluid to pass through the head of said piston with su f- Y flcient freedom at normal speeds ofrotation of the winding drum to avoid substantial increase in pressure in said cylinder, but operable by the rotation of said winding drum in excess of a predetermined speed to increase the fluid pressure in saideylinder, and means operable by such increasedpressure to arrest the rotation of said drum.

7. Governing mechanism for winches comprising a fluid-containing cylinder, a piston reciprocable therein having a head provided With a valved port operable to permit fluid to flow freely through said piston head into the pressure chamber of said cylinder, and also provided with a restricted port operable to permit the fluid to flow from saidpressure chamber through said head without substantially varying the pressure in said pressure chamber at normal speeds of reciprocation of said piston, but operable to resist the flow of fluid therethrough upon increase in speed of reciprocation in excess of a predetermined speed, means operable by the rotation of said drum to reciprocate said piston, and means operable by increase in pressure in said cylinder to arrest the rotation of the drum.

8. Governing mechanism for winches having a brake and a brake actuating lever comprising a fluid-containing chamber connected to and movable with said brake actuating lever, a piston reciprocable in said cylinder, having a head provided with a valved port permitting a free flow of the fluid into the compression chamber of the cylinder upon upward movement of the piston, but acting to prevent the fluid from flowing therethrough during the downwardmovementof the piston, and also provided with a restricted port permitting the fluid to flow therethrough Without substantially increas ing the pressure in said compression chamber during normal reciprocatlons of the piston,

. but operable to increase the pressure in the .sure Will impart bodily movement to'said cylinder and thcreby'cause' actuation of the brake, and means including an eccentrlc mounted upon the shaft of the winding drum for reciprocating said piston.

9. Governing mechanism for winches having a brake and brake. actuating lever comprising a plurality of fluid-containing cylinders mounted upon said brake actuating lever, tubular pistons reciprocably mounted in said cylinders, each having a head'provided with a-valved port acting to permit the fluid to flow freely from the compression chamber of the cylinder through said piston heao upon upward movements of the piston, but to prevent flow therethrough during the downward movement thereof, and also pro vided with a restricted port operable to permit the fluid to flow through the piston head "Without substantially increasing the pressure in the said compression chamber during normal speeds of movement of the piston, but a operable to increase the pressure therein upon increase in the speed of the piston in excess of a predetermined speed, a lever connecting' said pistons acting to cause them to reciprocate in alternating sequence, an eccentr c mounted on the shaft of the Winding drum, and means for causing said eccentric to actuate said lever.

In testimony whereof, I have signed my name to this specification.

NATHANIEL WARSHAW. 

